The longitude of India varies approximately from 68° East in Gujarat to 97° East in Arunachal Pradesh, a difference of 29°E. This will cause time in Arunachal Pradesh to be around two hours earlier than that of Gujarat. But the whole of India follows the Indian Standard Time (IST), which is taken at 82.5° East (passing through Mirzapur, UP). Thus, the Sun rises earlier in Arunachal Pradesh compared to Gujarat. Thus, both Assertion and Reason are true, and Reason is the correct explanation of Assertion.